Migration Of Aortic Smooth Muscle Cells Research Articles

W01.11 Non-lipid lowering effect of statins: Inhibition of human aortic vascular smooth muscle cell (VSMC) migration

W01.11 Non-lipid lowering effect of statins: Inhibition of human aortic vascular smooth muscle cell (VSMC) migration

Minocycline inhibits smooth muscle cell proliferation, migration and neointima formation after arterial injury.

The tetracyclines are antimicrobials that also inhibit expression of certain matrix metalloproteinases (MMPs). We conducted a series of experiments to determine if minocycline could inhibit MMP expression and limit human aortic smooth muscle cell (SMC) proliferation and migration. Analysis of SMC proliferation was performed after cells were grown in minocycline-incubated media. SMC migration activity was assayed in a micro-Boyden chamber. Western blotting revealed that minocycline reduced SMC production of MMP-2 in a dose dependent manner. Increasing doses of minocycline progressively reduced SMC proliferation to 49% of control values and limited SMC migration to 15% of control. When administered to rats with balloon injured carotid arteries, intraperitoneal doses of minocycline (70-100 mg/kg) reduced neointima formation by 76%, but were associated with liver toxicity. Higher doses were lethal and lower doses were ineffective. Minocycline, applied to injured arteries in a pluronic gel with a low pH, was also ineffective. In summary, minocycline lowers MMP-2 expression, reduces SMC proliferation and migration, and inhibits neointimal hyperplasia, but its efficacy is limited by systemic toxicity.

1P-0137 Interaction between the polyol pathway and non-enzymatic glycation on aortic smooth muscle cell migration and monocyte adhesion in a transgenic mouse model

1P-0137 Interaction between the polyol pathway and non-enzymatic glycation on aortic smooth muscle cell migration and monocyte adhesion in a transgenic mouse model

Differential PDGF secretion by graft and aortic SMC in response to oxidized LDL.

Smooth muscle cells (SMC) from prosthetic vascular grafts constitutively secrete higher levels of platelet-derived growth factor-AA (PDGF-AA) than aortic SMC. Lipid oxidation products accumulate in grafts and may stimulate PDGF production. The effect of oxidized low-density lipoprotein (oxLDL) on PDGF-AA secretion by aortic and graft SMC was compared. SMC isolated from canine thoracic aorta or Dacron thoracoabdominal grafts (n = 10) were incubated with native LDL or oxLDL (0-400 microg/ml) for 72 h. PDGF-AA in the conditioned medium was measured with enzyme-linked immunosorbent assay. OxLDL increased PDGF-AA production by graft SMC from 78 +/- 2 to 256 +/- 16 pg PDGF/microg DNA and aortic SMC from 21 +/- 1 to 40 +/- 2 pg PDGF/microg DNA. Native LDL had no effect. N-acetylcysteine inhibited oxLDL-induced PDGF increase. Both superoxide and H(2)O(2) stimulated PDGF secretion by graft SMC had little effect on aortic SMC. Our results suggest that PDGF production by graft (synthetic) SMC is more sensitive to stimulation by oxidative stress than aortic (contractile) SMC. Lipid oxidation products that accumulate in prosthetic vascular grafts can cause an oxidative stress, which stimulates PDGF production by graft SMC. PDGF can induce migration of aortic SMC onto the graft, contributing to the development of intimal hyperplasia.

Rat and human aortic smooth muscle cells display differing migration and matrix metalloproteinase activities in response to dexamethasone.

The steroid dexamethasone inhibits neointimal hyperplasia development in rats but not in humans. This study investigates the differential effects of dexamethasone on rat and human smooth muscle cell migration and matrix metalloproteinase (MMP) activity. Rat aortic smooth muscle cells were harvested from Sprague-Dawley rats. Human aortic smooth muscle cells were obtained from Clonetics. Boyden chamber migration assays were performed with chemoattractant (platelet-derived growth factor) and varying concentrations of dexamethasone (10(-9) to 10(-5) mol/L). Zymography of culture media was used to assess MMP activity, and Western blot analysis was used for quantification of MMP-2 and tissue inhibitor of MMP-2 (TIMP-2) secretion. Dexamethasone inhibits rat aortic smooth muscle cell migration in a dose-dependent fashion. An increase in concentrations of dexamethasone does not effect human aortic smooth muscle cell migration. Rat aortic smooth muscle cell MMP-2 activity is inhibited with dexamethasone in a dose-dependent fashion, and human aortic smooth muscle cell MMP-2 activity is unchanged with dexamethasone. MMP-2 secretion is inhibited with dexamethasone in rat aortic smooth muscle cells but remains unaltered in human aortic smooth muscle cells. Dexamethasone increases rat aortic smooth muscle cell TIMP-2 secretion, and human aortic smooth muscle cell TIMP-2 secretion remains constant. Dexamethasone inhibits rat aortic smooth muscle cell migration, MMP-2 activity, and MMP-2 secretion and increases TIMP-2 secretion. These effects are not observed in human aortic smooth muscle cells. These findings may explain why dexamethasone inhibits neointimal hyperplasia in animal models but is ineffective in humans. Inhibition of human smooth muscle cell migration in vitro may be useful in predicting the effectiveness of future therapeutic agents for treatment of neointimal hyperplasia in humans.

Antiproliferative effects of the antiallergic agent azelastine on human aortic smooth-muscle cells: an in vitro study.

The aim of the study was to examine the effects of azelastine on proliferation, clonogenic activity, cell-cycle, and migration of human aortic smooth-muscle cells (haSMCs) in vitro. HaSMCs were treated for 4 days with azelastine (1 micromol/L, 25 micromol/L, 50 micromol/L). Half of the treated groups were incubated again with azelastine, the other half received azelastine-free medium every 4 days until day 20. The growth kinetics and clonogenic activity were assessed. The cell-cycle distribution was investigated by FACS -- analysis and the migratory ability was evaluated. Azelastine inhibited the proliferation and the clonogenic activity of haSMCs in a dose dependent manner. A G2/M-phase block was induced and the migratory ability was significantly impaired. Azelastine has the potential to inhibit the proliferation of haSMCs. If a sufficient dose can be applied either systemically or locally it could be a valuable substance to prevent restenosis.

Quercetin inhibits human vascular smooth muscle cell proliferation and migration

Background. The French paradox has been associated with regular intake of red wine, which is enriched with flavonoids. Quercetin, a flavonoid present in the human diet, exerts cardiovascular protection through its antioxidant properties. We hypothesized that the beneficial effect of quercetin also could be related to the inhibition of vascular smooth muscle cell proliferation and migration. Methods. Human aortic smooth muscle cells (AoSMC) were grown in culture in the presence of serum. Quercetin inhibited the serum-induced proliferation of AoSMC. This inhibition was dose-dependent and not attributed to toxicity. Cell cycle analysis revealed that quercetin arrested AoSMC in the G0/G1 phase. The effect of quercetin on AoSMC migration was examined using explant migration and Transwell migration assays. Quercetin significantly decreased migration in both assays in a consistent manner. Finally, Western blot analysis of AoSMC exposed to quercetin demonstrated a significant reduction in the activation of mitogen-activated protein kinase, a signaling pathway associated with the migration of vascular smooth muscle cells. Conclusions. Quercetin inhibits the proliferation and migration of AoSMC, concomitant with inhibition of mitogen-activated protein kinase phosphorylation. These findings provide new insights and a rationale for the potential use of quercetin in the prophylaxis of cardiovascular diseases. (Surgery 2002;131:198-204.)

Adenoviral Delivery of a Leukocyte-Type 12 Lipoxygenase Ribozyme Inhibits Effects of Glucose and Platelet-Derived Growth Factor in Vascular Endothelial and Smooth Muscle Cells

The lipoxygenase (LO) pathway has been implicated as an important mediator of chronic glucose and platelet-derived growth factor (PDGF)-induced effects in the vascular system. Endothelial cells treated with 12LO products or cultured in high glucose showed enhanced monocyte adhesion, an important step in atherogenesis. We have previously reported that PDGF increased HETE levels in porcine aortic smooth muscle cells. Although several pharmacological inhibitors to the LO pathway are available, most lack specificity and may harbor undesirable side effects. Therefore, we developed a recombinant adenovirus expressing a hammerhead ribozyme (AdRZ) targeted against the porcine leukocyte-type 12LO mRNA to investigate the involvement of LO in glucose- and PDGF-mediated effects in vascular cells. Infection of porcine aortic endothelial cells with AdRZ reduced the level of glucose-enhanced 12LO mRNA expression as determined by quantitative, real-time reverse transcriptase-polymerase chain reaction. Reverse-phase HPLC and RIA analysis also revealed a corresponding decrease in glucose-stimulated 12HETE production in both the cellular and supernatant fractions. In the ribozyme-treated porcine aortic endothelial cells, there was marked inhibition of high glucose-stimulated monocyte adhesion. Infection with AdRZ also reduced PDGF-induced porcine aortic smooth muscle cell migration by approximately 50%. These studies demonstrate the efficacy of recombinant adenovirus expressing 12LO ribozyme in studying the effects of 12LO in vascular wall cells. They document an important role for the 12LO pathway in regulating inflammatory changes in endothelial cells and smooth muscle cells.

Extracellular mechanism through the Edg family of receptors might be responsible for sphingosine-1-phosphate-induced regulation of DNA synthesis and migration of rat aortic smooth-muscle cells

Exogenous sphingosine 1-phosphate (S1P) increased cytosolic Ca(2+) concentration, stimulated thymidine incorporation (DNA synthesis) and inhibited cell migration in rat aortic smooth-muscle cells (AoSMCs). Although exogenous sphingosine, a substrate of sphingosine kinase or a precursor of S1P, markedly induced the intracellular accumulation of S1P, the lipid failed to mimic the S1P-induced actions. In contrast, dihydrosphingosine 1-phosphate (DHS1P), an S1P receptor agonist, duplicated these S1P actions even though DHS1P was approx. 20-50-fold less potent than S1P. The pharmacological properties of DHS1P for the S1P receptor subtypes Edg-1, Edg-3, Edg-5 and Edg-6 were compared in Chinese hamster ovary (CHO) cells that were overexpressing the respective receptor. In these S1P-receptor-overexpressing cells, DHS1P was approx. 20-30-fold less potent than S1P for the displacement of [(3)H]S1P binding and inositol phosphate response in Edg-5-expressing CHO cells, as was the case for AoSMCs. However, it was slightly (not more than 3-fold) less potent than S1P in cells expressing Edg-1, Edg-3 or Edg-6. Of the above-mentioned four types of S1P receptor, Edg-5 was abundantly expressed in AoSMCs, as demonstrated by Northern blotting. These results suggest that the intracellular accumulation of S1P is not necessary for the S1P-induced Ca(2+) response, for the stimulation of DNA synthesis or for the inhibition of cell migration. Thus these S1P-induced actions might be mediated through extracellular (or cell-surface) S1P receptors in AoSMCs: Edg-5 might be a most important receptor subtype.

Extracellular mechanism through the Edg family of receptors might be responsible for sphingosine-1-phosphate-induced regulation of DNA synthesis and migration of rat aortic smooth-muscle cells

Extracellular mechanism through the Edg family of receptors might be responsible for sphingosine-1-phosphate-induced regulation of DNA synthesis and migration of rat aortic smooth-muscle cells

Migration of vascular smooth muscle cells is enhanced in cultures derived from spontaneously hypertensive rat

Migration of vascular smooth muscle cells (SMC) constitutes a common step in neointimal formation which occurs in several vascular diseases. Whether the migratory response of SMC derived from hypertensive animals is different to that of controls may provide a clue to the link between hypertension and atherosclerosis. We examined the migratory responses of SMC from cell cultures and ring explants (thin aortic ring segment) and compared these responses between normotensive and hypertensive rats at two different ages. Both scrape-wound assay and transwell chambers from cultured aortic SMC as well as aortic ring explant cell outgrowth models were employed. The aortae were obtained from male spontaneously hypertensive rats (SHR) and their normotensive counterpart the Wistar-Kyoto rat (WKY) at 5 and 20 weeks of age. Migration was induced by fetal bovine serum or platelet-derived growth factor (PDGF) and migrated cells were counted at different times following stimulation. We found that SMC migration exhibited a high sensitivity to serum (range of ED50: 2.2-3.6%), migration of SMC from 20-week-old SHR exceeded (by 46%, P<0.025) that of SMC from age-matched WKY and the difference became significant as early as 8 h after stimulation by serum. Chemotaxis induced by PDGF (2 h) exhibited similar differences. An elevated migratory response in SHR-SMC was also found in cells derived from 5-week-old rats in whom the blood pressure was normal. In younger animals, cell outgrowth from SHR aortic ring explants also accumulated more cells compared with WKY without a higher growth rate, thus suggesting that SHR-SMC have a higher migratory response ex vivo. In conclusion, aortic SMC migration appeared to be enhanced in various preparations from SHR. This difference also existed in young animals before the elevation of blood pressure occurred and might contribute partly to the role of hypertension as a risk factor for atherosclerosis.

2.P.375 Tissue factor pathway inhibitor inhibits aortic smooth muscle cell migration induced by tissue factor/factor VIIa complex

2.P.375 Tissue factor pathway inhibitor inhibits aortic smooth muscle cell migration induced by tissue factor/factor VIIa complex

4.P.121 Leptin stimulates rat aortic smooth muscle cell proliferation and migration

4.P.121 Leptin stimulates rat aortic smooth muscle cell proliferation and migration

THE INHIBITORY EFFECT OF HEPARIN FOR VASCULAR SMOOTH MUSCLE CELL PROLIFERATION OR MIGRATION IS NOT MEDIATED BY U-PA AND T-PA.

Previous works suggest the interesting possibility of an effect of heparin on vascular smooth muscle cell (SMC) replication and migration via a selective inhibition of the expression of t-PA and u-PA both of which may play major roles during intimal hyperplasia following endothelial injury. The present study was undertaken to evaluate in vitro the effect of heparin on the growth and migration of aortic SMC isolated from transgenic mice showing single inactivations of the t-PA and u-PA genes comparatively to SMC isolated from control mice. With regard to serum-induced proliferation and migration, all cell types showed similar responses. On control cells, heparin inhibited in a dose-dependent manner the expression of both t-PA and u-PA protein and mRNA. Heparin however, similarly affected the mitogenic and chemotactic activity of FCS for SMC isolated from control, t-PA or u-PA-deficient mice therefore showing that heparin inhibits FCS-induced SMC proliferation via mechanism(s) other than single inhibition of t-PA or u-PA expression by smooth muscle cells. © 1997 Elsevier Science Ltd

Tissue Factor Pathway Inhibitor Inhibits Aortic Smooth Muscle Cell Migration Induced by Tissue Factor/Factor VIIa Complex

Tissue factor (TF), a transmembrane glycoprotein, forms a high affinity complex with factor VII/VIIa (FVIIa) and thereby initiates blood coagulation. Tissue factor pathway inhibitor (TFPI) is an endogenous protease inhibitor of TF/FVIIa-initiated coagulation. We previously reported that TF was a strong chemotactic factor for cultured vascular smooth muscle cells (SMCs). In this study, we examined the contribution of FVIIa and the effect of TFPI to TF-induced cultured SMC migration. TF/FVIIa complex showed a strong migration ability, however, neither TF alone nor FVIIa induced SMC migration. TF/FVIIa treated by a serine protease inhibitor and the complex of TF and inactivated FVIIa (DEGR-FVIIa) did not stimulate SMC migration. Pretreatment with hirudin and the antibodies to alpha-thrombin and factor X had no effect on TF/FVIIa-induced SMC migration, although alpha-thrombin and factor Xa also induced SMC migration respectively. TFPI markedly inhibited TF/FVIIa-induced SMC migration in a concentration-dependent manner, but did not affect the SMC migration induced by platelet-derived growth factor (PDGF)-BB, basic fibroblast-growth factor (bFGF), or alpha-thrombin. These results indicate that the catalytic activity of TF/FVIIa complex is important on SMC migration, and TFPI can reduce SMC migration as well as thrombosis.

Rapamycin inhibits vascular smooth muscle cell migration.

Abnormal vascular smooth muscle cell (SMC) proliferation and migration contribute to the development of restenosis after percutaneous transluminal coronary angioplasty and accelerated arteriopathy after cardiac transplantation. Previously, we reported that the macrolide antibiotic rapamycin, but not the related compound FK506, inhibits both human and rat aortic SMC proliferation in vitro by inhibiting cell cycle-dependent kinases and delaying phosphorylation of retinoblastoma protein (Marx, S.O., T. Jayaraman, L.O. Go, and A.R. Marks. 1995. Circ. Res. 362:801). In the present study the effects of rapamycin on SMC migration were assayed in vitro using a modified Boyden chamber and in vivo using a porcine aortic SMC explant model. Pretreatment with rapamycin (2 ng/ml) for 48 h inhibited PDGF-induced migration (PDGF BB homodimer; 20 ng/ml) in cultured rat and human SMC (n = 10; P < 0.0001), whereas FK506 had no significant effect on migration. Rapamycin administered orally (1 mg/kg per d for 7 d) significantly inhibited porcine aortic SMC migration compared with control (n = 15; P < 0.0001). Thus, in addition to being a potent immunosuppressant and antiproliferative, rapamycin also inhibits SMC migration.

Effects of 17 -estradiol and progesterone on growth-factor-induced proliferation and migration in human female aortic smooth muscle cells in vitro

The significantly low prevalence of atherosclerotic cardiovascular disease in premenopausal women has been noted, and postmenopausal hormone replacement therapy (HRT) is associated with protection from this disease. The aim of this study was to investigate the effects of estrogen and progestin on growth-factor-induced vascular smooth muscle cell (VSMC) proliferation and migration in vitro. Two cell lines of human female aortic smooth muscle cells (AOSMCs) were used for the study. DNA synthesis was evaluated by [3H]thymidine incorporation into cells. Migration assay was performed using modified Boyden chambers. The presence of estrogen receptors was determined by Western and Northern blot analyses. [3H]Thymidine incorporation into AOSMCs was induced by 10 ng/ml EGF alone, the combination of 10 ng/ml EGF with 2 ng/ml b-FGF-induced and 1 nM PDGF-BB alone. Migration of AOSMCs was induced by PDGF-BB. Since 17 beta-estradiol (E2, 10(-9) M approximately 10(-6) M) inhibited the [3H]thymidine incorporation into AOSMCs stimulated by above mitogens and the 1 nM PDGF-BB-induced AOSMC migration in a dose-dependent manner, estrone (E1), estriol (E3) and progesterone (P) had no significant effects. The combination of P (10(-9) M approximately 10(-6) M) did not show any effect on these inhibitory effects of 10(-7) M E2. Preincubation of AOSMCs with the anti-estrogenic agent, tamoxifen (10(-6) M), significantly antagonized these inhibitory effects of 10(-7) M E2. These findings suggest that the inhibitory effect of E2 on VSMC proliferation and migration might be one of the factors involved in the decreased incidence of atherosclerotic cardiovascular disease in premenopausal women and postmenopausal HRT, and P might not affect these estrogenic responses.

Stimulation of migration of human aortic smooth muscle cells by vitronectin: implications for atherosclerosis.

Migration of smooth muscle cells into the neointima has been implicated in atherogenesis. Vitronectin, a serum factor that promotes cell spreading and attachment, accumulates in atherosclerotic human tissues. The aim of this study was to determine the role of vitronectin and its receptor (integrin alpha V beta 3) in migration of smooth muscle cells. Human aortic smooth muscle cell migration was studied in modified Boyden chambers. Expression of vitronectin receptor was determined by northern blotting of receptor mRNA and immunoprecipitation of receptor protein. Vitronectin dose dependently increased smooth muscle cell migration by an amount comparable to that induced by platelet derived growth factor, (PDGF)-BB. Antiserum to alpha V beta 3 diminished vitronectin driven migration. Northern blot analysis showed low constitutive expression of alpha V and beta 3 mRNA by smooth muscle cell and rapid induction with transforming growth factor beta (TGF-beta) and thrombin. Immunoprecipitation confirmed increased synthesis of the alpha V beta 3 vitronectin receptor complex by TGF-beta or thrombin. Smooth muscle cells pretreated with TGF-beta or thrombin showed increased vitronectin driven migration. cAMP suppressed induction of migration, but inhibition of protein kinase C increased it. These results show that vitronectin-induced human aortic smooth muscle cell migration is mediated by alpha V beta 3 vitronectin receptor and expression of the receptor is induced by TGF-beta and thrombin, which in turn induce vitronectin driven, vitronectin receptor modulated smooth muscle cell migration.

Osteopontin-Stimulated Vascular Smooth Muscle Cell Migration Is Mediated by β 3 Integrin

Osteopontin (OPN), a 41-kDa phosphorylated glycoprotein, has been detected in rat aorta and carotid arteries, and expression of its mRNA in blood vessels is strongly increased in response to vascular injury. To investigate the potential role of OPN in vascular pathophysiology, we studied the effect of rat OPN on aortic smooth muscle cell migration and proliferation in vitro. OPN enhanced the migration of rat smooth muscle cells in a time- and concentration-dependent manner with an EC 50 value of 46 ± 11 nmol/liter ( n = 5). The maximal increase in cell migration by OPN was 29-fold over basal levels. OPN-induced smooth muscle cell migration was inhibited in a concentration-dependent manner by the monoclonal antibody F11, which recognizes the rat integrin subunit β 3. In contrast, polyclonal antiserum recognizing the rat integrin β 1 subunit did not inhibit smooth muscle cell migration in response to OPN, but did block fibronectin-promoted migration. Moreover, OPN-induced smooth muscle cell migration was dependent on the presence of extracellular divalent cations and was significantly inhibited by anti-OPN antibodies. OPN did not stimulate [ 3H]thymidine incorporation into cultured smooth muscle cells, indicating that it selectively enhanced migration. In view of the pathological significance of arterial smooth muscle cell migration in the formation of intimal thickening, our results suggest that smooth muscle cell recognition of OPN, probably through the vitronectin receptor, α vβ 3, could play a role in the cells' response to vascular injury and especially neointima formation.

Interleukin-8. A mitogen and chemoattractant for vascular smooth muscle cells.

Interleukin-8 (IL-8) is a chemokine produced by a variety of cell types involved in atherogenesis and is chemotactic for neutrophils and lymphocytes. A recent study has shown that IL-8 is angiogenic and induces proliferation and chemotaxis of endothelial cells. The present study was undertaken to find out whether IL-8 is also mitogenic and chemotactic for vascular smooth muscle cells. IL-8 induced a concentration-dependent (0.1 to 10 nmol/L) stimulation of DNA synthesis and cell proliferation in both human and rat aortic smooth muscle cells. In addition, IL-8 stimulated smooth muscle cells to produce prostaglandin E2, which can inhibit IL-8-induced smooth muscle cell proliferation. In the presence of indomethacin (5 mumol/L), IL-8 (1 nmol/L) stimulated an increase in human and rat aortic smooth muscle cell number during a 3-day period of incubation by 61 +/- 16% and 59 +/- 7% (n = 4), respectively. IL-8 also increased DNA synthesis in human and rat aortic smooth muscle cells by 98 +/- 10% and 151 +/- 27% (n = 5), respectively. Moreover, IL-8 stimulated rat aortic smooth muscle cell migration by 20-fold over the control value, with an EC50 value of 0.83 nmol/L; this chemotactic activity of IL-8 was also potentiated by indomethacin. Exposure of smooth muscle cells to IL-8 caused rapid and transient expression of the immediate-early genes c-fos and zif268 mRNA.(ABSTRACT TRUNCATED AT 250 WORDS)